Looking for gearing opinions

[Flivver250]

My TJ has a NV3550 and 33" tires (which are really about 32 inches tall) and 4.56 gearing. Would I even notice much difference if I went to 4.88 gears? Where I need a tad more grunt is in the sand in high range. Low range is too low to go fast enough up steep dunes and in high range I am sometimes losing too much power during the climb. My gut tells me the 4.56 gears are just not low enough for the intended application and I don't want to go too much lower as average speed on the highway here is about 75MPH. BTW, engine is running fine and not suspect.

 

[Flivver250]

Caveat: My Jeep performs fine on the highways with acceptable power in the first four gears. I don't shift into fifth until I am going at least 60mph as it is a trifle doggie. The roads are fairly flat.

 

[jjvw]

I recently went from 33s to 35s with the nv3550 and 4.88. I notice the steeper gearing in all scenarios on and off road and would eventually like to bump up (down?) to 5.13. My biggest reasons are that 4H would be more useable in 1st, city streets would be nicer in 2H/1st and highway would be better in 5th.

 

[rouxbicon]

My TJ has a NV3550 and 33" tires (which are really about 32 inches tall) and 4.56 gearing. Would I even notice much difference if I went to 4.88 gears? Where I need a tad more grunt is in the sand in high range. Low range is too low to go fast enough up steep dunes and in high range I am sometimes losing too much power during the climb. My gut tells me the 4.56 gears are just not low enough for the intended application and I don't want to go too much lower as average speed on the highway here is about 75MPH. BTW, engine is running fine and not suspect.

I don't quite follow the idea of "low range is too low and high range is too high." Don't they actually overlap by a pretty good margin in a 231 t-case, and even by a little bit in a 241? I guess there can be an inconvenience frequently shifting back and forth between 4H and 4L, but changing axle ratios won't change the difference (overlap) between high and low range.

Or am I completely misunderstanding...?

 

[jjvw]

I don't quite follow the idea of "low range is too low and high range is too high." Don't they actually overlap by a pretty good margin in a 231 t-case, and even by a little bit in a 241? I guess there can be an inconvenience frequently shifting back and forth between 4H and 4L, but changing axle ratios won't change the difference (overlap) between high and low range.

Or am I completely misunderstanding...?

I think my 2H/4H is a bit too high. Mine has the 241. Right now, I use 4L/4th/5th more often now instead of 4H/1st compared to when I had 33s. I liked being able to use 4H/1st more often.

 

[rouxbicon]

Isn’t 4th low range exactly equal to 1st high range in the 241?

 

[rasband]

Isn’t 4th low range exactly equal to 1st high range in the 241?

I don’t know if it is, but there’s a lot of gears between there that would be a bit tiresome across dunes. I’d expect that means digging in pretty deep (and more importantly for this case, the higher gears would be lacking for the use case).

 

[Flivver250]

In the tall dunes speed is your friend. 4H can be just a smidgeon too high when you are going up the steep ones, and low range is a tad too low to attain the speed necessary to make the climb. In high range, if you are cresting a long, steep dune and have to downshift, that momentary pause between shifts is often all it takes to determine pass or fail. I manage, and usually make it first pass, but I think the slight lowering of gears may make a difference between dogging out at the top and still having enough grunt to go the last few yards. Traction is not the problem. A supercharger, Chevy V-8 or stroker would do it, but that is not in the cards for this sled in this country.

 

[jjvw]

Isn’t 4th low range exactly equal to 1st high range in the 241?

It is. The issue with my usage is that by the time I run out of gears in 4L, I'm going about 20-25mph at a noisy (for the speed) 3-4k rpm. If I want to go faster, I have to come to a near stop and shift to 4H/2H. I would rather do that sooner and just use 4H/2H more often to go fast and cover ground.